Re: optional features and AC_ARG_WITH

[Paul Eggert]

Stepan Kasal <address@hidden> writes:

> The samba developers interpreted --with-acl-support as a firm decision,
> so the configure script aborts if the acl prerequisities are not available.
>
> But the intention of the distribution builders was rather like ``I'd like
> to have acl support, if possible''.

I am starting to see the problem here.  The Autoconf manual says that
the interpretation of --with-foo is up to the developers.  The Samba
developers apparently came up with an interpretation that is
inconvenient for some distributors.

However, I still don't see the full problem here.  Why can't you
simply avoid --with-acl entirely, when running ./configure?  Won't
that give you ACL support if possible, and avoid it if not?

Also, is there some advantage to the way that Samba is doing things,
for people other than yourself?

Perhaps all we need to do is to write up a description of this issue
in the Autoconf manual, and advise people to use a solution that is
friendlier to distributors.

> The behaviour of samba package, as described above, seems to be correct:
> If the option is given, the configure script is not allowed to switch it
> off because it _thinks_ there are missing prerequisities.

The Autoconf manual says that Samba's current behavior is allowed, but
is not required.  We could tighten things up a bit, or at least warn
about the problem.


> Gregorio Guidi writes:

> On the other hand: currently, if I want to send a patch to a
> developer to add a missing AC_ARG_WITH to configure.ac, I can't just
> add AC_WITH_ARG, but I must also add the logic to deal with all the
> user specified cases, that is, add two or three if statements,
> almost rewriting all the code.

Fom the other email I understand that you want to have --with-foo
option that doesn't crash if package FOO isn't available.  But now it
sounds like you have a more complicated scenario in mind, one that
involves input from the user.  Could you please explain this a bit more?